Use mapped memory for uploading large textures.

gpu/command_buffer/client/mapped_memory.cc

Index: gpu/command_buffer/client/mapped_memory.cc
diff --git a/gpu/command_buffer/client/mapped_memory.cc b/gpu/command_buffer/client/mapped_memory.cc
index 6d57af4ed57204e62156f215d3af59143b658da7..0151c43d2369560a952630fa80632ad38bc5dd5c 100644
--- a/gpu/command_buffer/client/mapped_memory.cc
+++ b/gpu/command_buffer/client/mapped_memory.cc
@@ -81,6 +81,11 @@ void* MappedMemoryManager::Alloc(
     }
   }
 
+  if (max_free_bytes_ != kNoLimit &&
+      (allocated_memory_ + size) > max_free_bytes_) {

[jbauman, 2015/06/09 02:30:13]

This wasn't intended to be a hard limit, but rather to prevent it from using
memory unnecessarily (hence the name unused_memory_reclaim_limit for the
argument to the function). I think you should instead have a flag that treats it
as a hard limit, and only use that flag in the new cases.

[David Yen, 2015/06/09 17:07:08]

Ok, I've separated out this concept and added max_allocated_bytes_ that limits
the maximum number of bytes we allocate.

+    return NULL;
+  }
+
   // Make a new chunk to satisfy the request.
   CommandBuffer* cmd_buf = helper_->command_buffer();
   unsigned int chunk_size =
@@ -140,4 +145,26 @@ void MappedMemoryManager::FreeUnused() {
   }
 }
 
+void ScopedMappedMemoryPtr::Release() {
+  if (buffer_) {
+    mapped_memory_manager_->FreePendingToken(buffer_, helper_->InsertToken());
+    buffer_ = nullptr;
+    size_ = 0;
+    shm_id_ = 0;
+    shm_offset_ = 0;
+
+    if (flush_after_release_)
+      helper_->CommandBufferHelper::Flush();
+  }
+}
+
+void ScopedMappedMemoryPtr::Reset(uint32_t new_size) {
+  Release();
+
+  if (new_size) {
+    buffer_ = mapped_memory_manager_->Alloc(new_size, &shm_id_, &shm_offset_);
+    size_ = buffer_ ? new_size : 0;
+  }
+}
+
 }  // namespace gpu